1. Field of Invention
The present invention relates to a semiconductor process. More particularly, the present invention relates to a method for removing a photoresist layer.
2. Description of Related Art
In the manufacturing process of the semiconductor, there are many etching processes using photoresist layer to define patterns. However, after the etching process, the photoresist layer must be removed to perform the subsequent processes.
The conventional photolithography process comprises steps of coating a photoresist layer over a wafer going to be etched and then performing an exposure process on the photoresist layer by using a mask with a specific pattern so as to transfer the pattern on the mask onto the photoresist layer. Hence, the property of the exposed portion of the photoresist layer is changed. Thereafter, the portion of the photoresist layer which is going to be etched is removed and the remaining portion of the photoresit layer is served as a mask in the etching process performing on the wafer. After the etching process is performed on the wafer, the remaining portion of the photoresist layer is removed. The currently etching process includes anisotropic etching using high density plasma and, at the same high density plasma tool, the photoresist layer is in-situ removed by being bombarded by the oxygen plasma. However, in the high density plasma process for removing the photoresist layer, the oxygen atoms with high energy in the plasma would penetrating through the etching stop layer under the dielectric layer and the metal silicide layer under the etching stop layer is oxidized by the penetrating oxygen atoms. Therefore, the electrical performance of the metal silicide layer is changed and the performance of the device is affected as well.